The field of the invention relates to a braking system used in a shopping cart. More specifically, it relates to a shopping cart with a brake that must be disengaged by the operator to allow movement of the shopping cart. The invention also discloses that, when the shopping cart is nested with other shopping carts, the braking system is disengaged to allow multiple shopping carts to be moved.
Shopping carts are convenient transportation devices that are used when one or multiple items are purchased at a store. Most commercially available shopping carts do not employ a braking system in the shopping cart. One problem with currently available shopping carts is that they can roll away if the cart is placed on a slope. Many people at one time or another have had a shopping cart roll away, or have seen a shopping cart roll down a parking area and stop when the shopping cart came in contact with a car or other object. The ideal shopping cart would provide the convenience of easy mobility when in use, and sufficient braking capacity when the cart is not being pushed or moved. The ideal design would need to be rugged enough to withstand the daily use and pounding imposed on today's shopping carts, and provide safety to users so fingers and clothing are not pinched by the braking mechanism. Simplicity of the design of the shopping cart is important for manufacturing, user understanding, and longevity of the mechanism and the braking surfaces. Several inventions have tried to produce a shopping cart with these features.
U.S. Pat. Nos. 1,709,527, 1,861,958, 2,988,175, 4,018,449, 5,325,938, and 5,735,367 utilize a cable, chain, or other flexible member running either inside a tube, or inside a sheath that is connected to a tube on the shopping cart to manipulate a brake that is applied to the wheel. U.S. Pat. Nos. 2,958,537, 3,095,211, 3,501,164, 4,384,713, 4,840,388, 4,976,447, 5,499,697, 6,199,878 use a rod located outside the frame tube of the shopping cart. All these prior patents provide a link from the handle to the brake, but the linking mechanism is fragile, and subject to intentional or unintentional damage. What is needed is a linkage from the handle to the braking mechanism that is solid, and protected.
Another valuable attribute of the invention is that the operation of the braking mechanism should be easy to use and operate. The method of de-activating the brake should be the same as using the shopping cart. U.S. Pat. Nos. 2,958,537, 5,499,697 require the user to lift the handle to deactivate the brake. U.S. Pat. No. 6,199,878 requires the user to rotate the handle. U.S. Pat. No. 4,976,447 require the user to pull the handle. U.S. Pat. No. 4,840,388 requires the user to grasp or squeeze the handle. None of the listed patents require the user to perform the function of pushing the cart to deactivate the brake, or resting on the handle as the cart is being pushed. In addition, most of the designs require the user to overcome a spring that keeps the handle or brake engaged.
Still another valuable attribute of the invention would involve a braking system that does not reduce the life of the tires on the shopping cart. U.S. Pat. Nos. 3,095,211, 3,501,164, 4,018,449, 4,840,388, 4,976,477, 5,325,938, 5,499,697, 5,735,367 and 6,199,878 utilize a braking system that rubs on at least a part of one tire of the shopping cart. U.S. Pat. No. 2,958,537 uses a pawl that engages a ratchet tooth, and when the pawl in engaged, the wheel is locked into position causing the tire to slide on the ground. What is needed is a braking system that does not abrade the tire to cause the braking of the shopping cart.
While the prior art provides the basic function of slowing or stopping a shopping cart, none of the prior art provides a braking system that disengages the braking system while the cart is being pushed, where the connecting rod is protected from normal and abnormal damage, or the braking system does not abrade the tire surface. The disclosed invention provides unique solutions to each of these previously undisclosed combined improvements.